[26] Biochemistry of Muscle Contraction Flashcards
What is the primary function of muscles?
To enable movement of the body by contracting and relaxing.
What is a muscle fiber?
A single muscle cell that contracts in response to stimulation.
What is a myofibril?
A basic rod-like unit of a muscle cell that contracts.
What are the main components of a myofibril?
- Sarcomeres
- Actin filaments
- Myosin filaments
What is a sarcomere?
The functional unit of muscle fibers where contraction takes place.
What is the role of actin in muscle contraction?
Actin is a protein that forms thin filaments that slide past thick filaments (myosin) to cause muscle contraction.
What is the role of myosin in muscle contraction?
Myosin is a protein that forms thick filaments that interact with actin filaments to cause muscle contraction.
What is ATP (Adenosine Triphosphate)?
ATP is a molecule that provides energy for muscle contraction.
How does ATP contribute to muscle contraction?
ATP provides the energy for the power stroke of the myosin head, which causes the sliding of actin filaments.
What is a motor unit?
A motor neuron and the muscle fibers it innervates.
What is a neuromuscular junction?
The synapse or connection between a motor neuron and a muscle fiber.
What is the role of acetylcholine in muscle contraction?
Acetylcholine is a neurotransmitter that triggers muscle contraction by binding to receptors on the muscle fiber’s membrane.
What is the sliding filament theory of muscle contraction?
A theory that explains muscle contraction as the sliding of actin filaments over myosin filaments.
What is an antagonist muscle?
A muscle that opposes the action of another muscle (agonist).
What is an agonist muscle?
A muscle that contracts to produce a certain movement.
